All posts by Debjyoti Bardhan

Is a science geek, currently pursuing some sort of a degree (called a PhD) in Physics at TIFR, Mumbai. An enthusiastic but useless amateur photographer, his most favourite activity is simply lazing around. He is interested in all things interesting and scientific.

Shortage of funds has hit the scientific laboratories badly. This is quite evident from the attitude Fermilab has towards the deceased Tevatron. Fermilab is planning to recycle many parts of the once-biggest particle collider for other experiments. It’s to save cost, they clarify.

The CDF detector in Tevatron is now being raided for valuable, and not-so-valuable, parts.

Parts, parts…

Of course, there is nothing wrong in that – in fact, this is a good practice. However, given the amount of history the Tevatron has, many people are frowning. The ex-spokesperson for the CDF detector at Tevatron, Rob Roser says:

Some parts are worth pennies, but in this budgetary climate, even pennies are worth saving

The Tevatron was the biggest beast in the particle physics world till the Large Hadron Collider (LHC) came onto the scene. It has fulfilled all of the expectations and has done more. It discovered the top quark, accurately measured the mass of the W and Z bosons and was instrumental in the Higgs search, especially in the low mass range. The Tevatron probed the Higgs decaying to two photon channel and, now it seems that this is the most promising channel.

However, now the collider parts are being utilized for some other experiments. Demands are being met for photomultiplier tubes (PMT’s). These are used to catch light as particles deposit energy while travelling through the detector material.

Tevatron after death: Just some squiggly lines on the ground?

Looking into the Future

There are other things planned in the near future. Fermilab is all set for lepton colliders, which will collide particles like electrons and positrons, or muons-antimuons. The muons can change to electrons and this process will be studied in greater detail by the new lepton collider. This process should answer certain questions about the electroweak force and put strong bounds on the different constants in the electroweak theory, especially the magnetic moment of the muon. This is the so-called ‘g-2’ (g minus two) experiment. The muonic magnetic moment, supposed to be just 2, is actually a bit more. The difference between the electronic and muonic magnetic moments is due to the difference in masses. The electron to muon process should involve hadronic processes as well and this new experiment could yield very strong bounds on these hadronic processes. The hadronic processes from leptonic processes can indicate supersymmetry and, thus, can tell tales about Physics beyond the Standard Model.

There are also many long baseline Neutrino experiments planned. Fermilab’s own MINOS experiment has to be upgraded and the data made more precise.

Even in death, the Tevatron is fuelling research, this time donating parts of itself for future experiments. Scavenging may be a strong term to use for Fermilab and what it is doing to the Tevatron, but there is no doubt that the desecration of the giant will disappoint a few.

The giant has no place to go, as of now! Or maybe, just one place too many. The Square Kilometer Array (SKA), the biggest array of ground based radio telescopes, is now hanging in the balance searching for a site. The two contenders are Australia and South Africa.

An artist's impression of the SKA. (Courtesy: Wikimedia Commons)

About the SKA

The SKA costs a whopping 1.5 billion euros. The mammoth array is set have a collecting are of 1 square kilometer and be sensitive over a very wide range of frequencies. The radius of the array will be at least 3000 km from the central core (a few telescopes clustered at the center) and the total data uplink-downlink will dwarf even the total global Internet data transfer, when it will actively observe! This means that the computers handling the data will have to be state-of-the-art as well as the means to transfer data. It will look into the Universe, as it was about 300,000 years after the Big Bang till the time when it became transparent, i.e. the reionization era.

The core array of the SKA. It is set to have three different sub-arrays having antenna probing different frequency regimes within the radio. (Courtesy: Wikimedia)

Construction of the array is set to begin in 2016 and end in 2019. It will see first light sometime in 2020.

The two rivals

The Australian side is promising the core of the array in the west of the continent and the outer arms and outstations stretching across the sea to New Zealand. The South African contingency plans its core in the Karoo region, North Cape, in the northern part of the country, and the outer arms are going to stretch to eight neighbouring countries!

The requirements for selecting a site for a radio telescope include arid conditions, radio-quiet regions and low human activity.

The site will be finalized by the end of this year and only then will the SKA construction start off!

Scientists have hit a new low when it comes to size! The newest size of a transistor is just one atomic radius and it is made of phosphorus. A group of physicists from the University of New South Wales and Purdue University have created a transistor out of a single phosphorus atom embedded in a silicon crystal. Moore’s law has been broken, once and for all!

An STM image of the phosphorus atom placed on a Silicon substrate. The surrounding electrodes are the drain and source (see next image). (Courtesy: Arstechnica)

Quantum Mechanics and Choices!

What more, the transistor, instead of relying on the binary electronic states of ‘on’ and ‘off’ can rely on a superposition of quantum states, using so-called qubits. Qubits don’t represent just one of the two positions, but a multitude of all the possibilities, as prescribed by quantum mechanics.

Qubits will help realize the making of quantum computers, and of this, scientists are sure! The computers will be extremely small (for obvious reasons), very fast (information relay over tiny scales and the huge number of qubit states to utilize), energy efficient (no heat dissipation) and be able to solve a huge number of problems within a fraction of a second.

Moore’s Law

Even Moore’s law is happily in trouble! Moore’s law states that every eighteen months, the density of transistors on a chip doubles! Moore’s law has been scaled down to the scale of one atom! It is safe to say that it cannot go down any further.

The colour gradient image of the potential across the neighbourhood of the single phosphorus atom. The G, S and D refer to the gate, source and drain. So-called Field Effect Transistor (FET's) are supposed to regulate the passage of current from the source to the drain, using the voltages applied at the gates (Courtesy: Nature article)

Andreas Heinrich, a physicist at IBM, says the following about this work:

This is at least a 10-year effort to make very tiny electrical wires and combine them with the placement of a phosphorus atom exactly where they want them.

The deposition of the single atom at a precise position was done using a scanning tunneling microscope (STM). The STM was used to ‘cut’ the ‘groove’ into the silicon. Phosphine gas was then used to deposit one atom of phosphorus. It was then covered with a few layers of silicon.

The ‘magic bullet’ has been on the minds of medical researchers for a long time. The only problem is that no such thing exists right now, but medical research has been looking at every possible pathway to get a hint of creating such a thing. Now, a “DNA robot” has been made that specifically targets cancer cells. This has been done using a technique called ‘DNA origami’!

The DNA robot. The wrapping is done with the payload inside. Then it is released when the target appears. Taken from the paper by Shawn et. al. (Courtesy: Science)

A great merger!

It’s a merger between digital logic, nanobots and biological molecular pathways. DNA can be folded into very specific shapes, using a technique called ‘DNA Origami’, the name obviously being inspired by the paper art. Then, specific drugs molecules can be ‘loaded’ onto these DNA robots and sealed with molecules called ‘aptamers’. Aptamers are molecules, made up of a small number of amino acids, which are the building blocks of large protein molecules. These aptamers can recognize the molecular signature of the delivery site and then can unlock the ‘robot’, allowing it to discharge its payload at the site (picture above). This very specific delivery system is the prized mechanism in cancer research at this moment. Generally, cancer drugs (whenever available) do a lot of harm to the healthy cells as well.

The work, led by Shawn Douglas of Wyss Institute, Harvard University, has been published in Science. He goes on to say the following to BBC News:

We’ve been working on figuring out how to build different shapes using DNA over the past several years, and other researchers have used antibodies as therapeutics, in order to manipulate cell signalling, and yet others have demonstrated that aptamers can be used to target cancer cell types. The novel part is really integrating all those different pieces and putting them together in a single device that works.

Why DNA? And what’s next?

But, why DNA for the building block for the robot? Simple. DNA is found in all cells and the body recognizes its own DNA. Thus, making the robots using DNA will eliminate any chances of toxicity or of non-recognition by the healthy cells of the body.

So what’s next? As always in science, and more so in medical science, the next step is optimization! A huge number of tests have to be performed in order to gauge the efficacy of this new technique.

Cancer research is surely at the brink of a big discovery. There have been frequent knocks on the closed doors, and sometimes, like this present case, a punch through. It’ll be interesting to predict when that door will finally fall!

Exotic is the word! Italian physicists have discovered traces of rare nuclei containing an exotic form of matter – hyperons. They have just discovered a hydrogen nucleus with 6 nucleons, which includes 4 neutrons, 1 proton (and thus hydrogen) and one uncharged hyperon called lambda!!

The exotic side of the Universe

Hyperons are particles, which are made up of quarks, just like protons. But, unlike protons, they are short-lived, much heavier and contain the so-called strange quark. They are thus called strange baryons! If a nucleus contains such hyperons, the nucleus is called ‘hypernucleus’.

The Italian scientists have found a hypernucleus called ‘hydrogen six Lambda’ (6ΛH, Λ=Greek letter, Lambda), which means that it is a hydrogen nucleus (i.e. has 1 proton), with six nucleons altogether (i.e. 5 particles other than the proton) and that one of them is the Lambda baryon. This says that the other four particles are all neutrons. The 6ΛH was predicted in 1963, but only now have physicists at Instituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Frascati (INFN-LNF) working on this experiment called FINUDA found a signature of it. The finding is due to appear in an issue of the Physical Review Letters (PRL).

The hyperon makes it possible to detect this hydrogen nucleus having as many as 4 neutrons. Hydrogen five (5H), i.e. without the Lambda, exists for just 10-22 s, which is too short to measure leave alone trap and study the nucleus. The presence of the strange particle boosts the lifetime by a factor of a trillion, taking it to 0.1 nanosecond, which is long enough for physicists to measure and study. Note that this timescale is still way too small for daily life!

Producing the hyperhydrogen

The hyperhydrogen is produced in an indirect way. The FUNIDA collider collides electron-positron beams. This gives rise to a phi-meson (with a small probability). This phi-meson can decay into two other mesons – the K meson and the anti-K meson. When the anti K-meson (which contains a strange quark) interacts with a lithium nucleus, it can produce a 6ΛH and pi-plus meson. When physicists detect the pi-plus meson, they know that a 6ΛH has been created.

Producing hyperhydrogen (Courtesy: FUNIDA experiment collboration)

FUNIDA experiments have also been able to produce 4ΛH, having 2 neutrons. They are produced more readily than 6ΛH and can be studied with greater ease as they exist for a longer time than the 6ΛH.

Clues into strangeness

Physicists are hoping that such studies will yield valuable clues into the nature of strange forms of matter. Another interesting challenge will be to synthesize nuclei having two strange particles, rather than just one! Producing helium or lithium nuclei with strange particle is also on the cards.

He is an honest liar. And he is impressive! James Randi, former magician – or as he would like to be called performer – has made a name being the most formidable foe that magicians or psychics have ever faced. He is one of them – only brutally honest! He would tell the audience that he is going to lie to them, then lie to them and then tell them again that he lied to them, yet his audience will be left amazed. He had the arrogance in his personality and dexterity with his performance to call himself ‘Amazing’; ‘the Amazing Randi’ quickly became a TV celebrity.

I know what you did there. Your argument is invalid!

Challenging the fraudsters

His unwillingness to just lie low and let the powerful charlatans carry on their money-making tricks has made him more famous than ever. He has set up his own organization dedicated to exposing tricksters, claiming to have supernatural powers. There is a lot at stake too! The James Randi Educational Foundation (JREF) offers a prize of $1,000,000 to anyone who would prove that he/she is a psychic or a possessor of whatever supernatural power they claim! The prize has never been claimed since inception and, what more, many have backed out of the challenge; well-known TV charlatan and self-proclaimed psychic Sylvia Brown is one such example. So what’s at stake for the people taking the challenge? Their entire reputation.

On TV in a grand style!

Now, Justin Weinstein and Tyler Meason are filming a documentary called ‘An Honest Liar: The Story of the Amazing Randi’. This documentary will trace Randi as he does what he has been the best at doing – uncovering frauds. The film will track the adventures of “an Ocean’s Eleven-type team for a carefully orchestrated exposure of a fraudulent religious organization”, as Randi puts it. The documentary will also feature well known skeptics like Adam Savage, Richard Dawkins, Bill Nye and Neil deGrasse Tyson.

Space is filling up with junk and the Swiss are not very happy about it. They would like to make space look like the bedroom your mother always wanted you to maintain. To achieve this, they are launching a satellite to clean up space junk. The satellite has been christened CleanSpace One.

An artist's impression of CleanSpace One (Courtesy: AFP/Getty Images)

The Swiss space center at Ecole Polytechnique (EPFL) at Lausanne wants to make this ‘janitor satellite’ to clear space of all the dead rocket bits, the different booster stages and pieces of old satellites. There are more than a million shreds of junk out there, orbiting at 18,000 mph, each posing threats ranging from mild to severe.

The satellite will be launched in another 5 years and is expected to cost SFr 10 million (SFr = Swiss Franc) or $11 million.

A Big Problem!

To give you a sense of how serious the problem of junk is, we need consider the US satellite Iridium-33. It exploded when the obsolete and abandoned Cosmos-2251, a Russian satellite, hit it in Feb, 2009. This in turn created more fragments of junk, which may turn out to be just as disastrous in future.

CleanSpace One will pursue junk pieces and then grab them with a robotic hand. After it has cleaned up most of what it intended, it will just drop down through the atmosphere, burning up much before it reaches Earth, incinerating the junk along with itself.

Just the beginning…

And this is just the first step, says EPFL. Says Volker Gass, director at the space center, on the EPFL website:

We want to offer and sell a whole family of readymade systems, designed as sustainably as possible, that are able to de-orbit several different kinds of satellites.

Entire Europe is reeling under an intense cold spell. This is the worst that Europe has seen since February 1991. NASA’s Terra satellite reveals this with a photograph. Most of the area is blue, indicating a temperature much below the normal. The data stretches from January 25th to February 1st. The “normal temperatures” are estimated from data ranging from January 25th to February 1st over the years 2001 to 2011. And this is just the land temperature. Oceans and lakes appear in gray. This was NASA’s photo of the day today.The image that NASA's Terra satellite took of the entire landmass of Europe. The scale (below) shows how further below the normal the temperatures across Europe are. (Courtesy: NASA)

This year’s tremendous cold throughout the Northern Hemisphere is a not a sign of global warming, but of erratic climate conditions, which might be indirectly linked to global warming.
Jeff Masters explains it as being due to the Jet streams, or rather their anomalous flow patterns. Jet streams are wide streams of air in the atmosphere and, like ocean currents in the sea, they separate different pockets or regions of air from one another. One of them blows from the west to the east along the middle latitudes, separating cold air from the north from the warmer air packets to the south. This year the Jet stream pattern has been very convoluted and the usual stream is now flowing further south. This means that the cold air front has descended southwards, covering much of Europe and leading to this spell of intense cold.

News from the Himalayas

In related news, a different perspective tab on global weather provides both relief and astonishment. While climatologists have already given their prediction of fast melting of glaciers in the Himalayan regions, it seems that the glaciers have not melted much in the last year or so.
Prof. Jonathan Bamber, glaciologist at Bristol Glaciology Center, University of Bristol, says that this is extremely unusual that the ice mass loss is “not significantly different from zero”. However, the results of the climate scientists fall bang on for the mass loss experienced by Antarctica, Arctic, Greenland and the Alaskan permafrost. The data anomaly for Himalayan regions might indicate some region-specific variation that is difficult to incorporate into models.

Climate denial

This should be music to the ears of climate deniers and provide some much needed ammo in their depleted armory. They have always viewed the conclusions as being falsely alarmist and have called them a fraud. However, outright denial is something to be guarded against. Simon Cook warns:

All too often in the past, media reports have presented a ‘black and white’ view of glacier response to climate change. The reasons for this complex global picture are not clear: some places warm more than others, some places experience more precipitation and, hence, snowfall to maintain glaciers is in positive or neutral balance. What is clear is that more research is required to evaluate the response of glaciers to climate change.

In the absence of an alternative to Earth, we ought to do our bit to prevent the ruin of this planet. And we can start off by taking scientists a bit more seriously.

The health of men being sent to space has always been a huge concern for space organizations, and NASA has come up with a solution that borders on the edge of being a miracle. NASA has made the NASA Biocapsule – a tangle of carbon nanotubes that will be used to contain particular cells and even medicinal substances inside it. It’s tiny, inserted into the skin, non-reactive, fast-acting and virtually indestructible!

The biocapsule. Courtesy: gizmodo.com

How it works

This is how this contraption works – A small incision is made on the body of the astronaut, barely skin deep. The nanotube, along with whatever package it is wrapped around, is then inserted subcutaneously. The wound is then either stitched up with a couple of stitches and the astronaut is good to go!

The Biocapsule has been made by Space Biosciences Division at NASA Ames, like all other medical technology made exclusively for NASA. Dr. David Loftus has been awarded a patent for leading the group, which came up with this creation.

The Biocapsule might contain cells, which can dispense hormones should the body require it. For example, if one is diabetic, or if one develops such a condition during a long stay in outer space, the capsule might contain pancreatic islet cells (or some cells which behave like these). Should the body need insulin, the cells will detect the low amounts in the blood and automatically start secretion. Dr. Loftus explains:

The capsule would contain pancreatic islet cells (from animals) or would contain engineered cells designed to behave like pancreatic islet cells, with both glucose-sensing and insulin secretion function. Patients with low-insulin requirement might benefit from implantation of a single capsule (containing perhaps a million to 10 million cells); patients with higher insulin requirement might require implantation of more than one capsule.

The Biocapsules can handle diseases as serious as radiation sickness. The Biocapsules can be used to contain cells that release the hormone G-CSF (Granulocyte colony-stimulating factor), which is a standard treatment for cancer patients undergoing radiation therapy so that they don’t develop any side-effects. Cells capable to detecting high exposure can be planted inside these Biocapsules and these will discharge the G-CSF hormone when triggered by the high radiation dose.

The Best Aspect of it all!

Now here is the coolest aspect of this miracle – it can be easily used on Earth! This is a potential explosive keg of medical revolution having the size of a few microns. It can save millions of lives on Earth, were it to go public! This might even be used to administer very local dosages of substances, which might be harmful to other organs, if it spreads.

With the closest doctor being a few thousand kilometers away, the tiny bundle of security might be the life of an astronaut. Literally!

The Higgs search gets hotter and hotter. Recent analysis of old data have raised the confidence level of the Higgs detection from the older value of 3.8-sigma overall to a much healthier 4.3-sigma, as indicated by the two papers sent for publication, one by CMS and the other by ATLAS. The Compact Muon Solenoid (CMS) detector group had given the confidence level of 2.5-sigma. Now, with the analysis of more data, they have pushed it up to 3.1-sigma. Remember that a 5-sigma confidence level is what you need for tagging something as a discovery – so 4.3-sigma, though exciting, is not momentous.

A Higgs simulation at CMS

There – but not quite there

The results overwhelmingly predict a Higgs mass in the range of 124-126 GeV, which is exactly what scientists had reported on December 13th.

A 5-sigma means that one is 99.99997% sure, while a 4.3-sigma result means that scientists are 99.996% sure that the identified peak is the Higgs peak.

Just a joke!

This is just an improvement over the ‘initial’ December announcements by CERN. The data is not new, since the LHC hasn’t been taking any since November, but a more thorough analysis has been done and this is what it says. I suspect that this is as far as CERN can go at the moment with the Higgs confidence levels, and they will require much more data to be completely sure.

The 3.8-sigma confidence levels shouldn’t be taken too seriously. There have been peaks of this confidence level, but they had vanished. Fortunately, this hasn’t.

A new chapter

We should have to wait another year or so before the LHC can give something definite on the Higgs search. Now that the LHC is temporarily closed down for mandatory maintenance efforts, the big bosses, meeting at Charminox, France, are discussing the energy and the luminosity it will be tuned to when it opens later this year. The scale up to 8 TeV in energy is expected, but the luminosity is not yet revealed.